I have a 97 xj6 x300 with 85,000 miles and i need some help identifying these codes

 

Before replacing anything on the vehicle, be sure the battery is fully charged. Use a voltmeter to read the voltage across the battery terminals with the ignition in the OFF position. There should be a minimum of 12.6 volts present. If not, charge the battery for at five hours at 2 to 5 amps and retest the voltage. If the voltage is still less than 12.6 volts, replace the battery.

Have you removed the coil units to see if there is oil present in the spark plug wells? Oil can cause the coils to misfire resulting in some of the DTCs you list above.

 

I have and there was just a tad on the spark plug when i pulled it out and a little bit on the side of the actual well for the spark plug. And its only on the furthest 2 cylinders from the firewall

 

You can download the DTC Summaries manual from this forum at the link below. This will give you the model-specific Jaguar definitions and possible causes of each code:

Jaguar X300 DTC Summaries 1996-1997

Have you performed any service recently that could have disturbed the oxygen sensor connectors on the firewall? Disconnected or swapped O2S connectors could lead to codes like yours.

Cheers,

Don

 

I have not done anything beside an oil change and brakes. I just recently got the vehicle so this is all new to me but i did check all spark plugs and coils, the coils didnt seem bad to be causing such a rough misfire and a little oil as mentioned abobe.The whole car shakes when id rove it around the speed would like lose pressure or something with no movement on the throttle. Also to note it is very hesitant to get up to speed i feel im using more throttle than necessary to get up to speed. Once up to speed it responds faster, no high idle it idles as it should but idk im at a loss rn

 

Also cleaned the MAF sensor as well as the throttle body a few days ago but it still reads the same codes

 

unplug maf when the car’s running and see what happens. almost aftermarket coils do fail suddenly and the misfire detection is very bad on these cars. unplugged rear O2s can cause crappy running.

by the way at the minimum you’re gonna need a $5 ELM327 scanner on ebay, running around to autozone is gonna get real boring fast

 

I live right next to an autozone that surprisingly is never busy(knock on wood) but i will need to get one soon but as of now this it what I've found. Also to note this very annoying rattling noise on cold start every time. I immediately turn it off and back on to try and mimic it but it only does it after sitting for a while. But for now i think i need some new hoses for these suckers right here

 

I do have a video of rattling noise but it won’t upload

 

cold start rattle is the timing chain tensioner, when it sits it loses pressure and you’ll have a rattle for a second. not a big deal but they sell an updated part to take care of that

 

Do you happen to know the part number ?

 

I would also suggest they clear the codes, drive around the block and then scan again and see what comes back.

 

Hi mh.anthony6,

Ordinarily I would agree with Scaphan, but in your case it sounds as though your engine really is misfiring in multiple cylinders. Driving it in that condition can allow large quantities of unburned fuel into your catalytic converter, which will destroy the converter. Better to resolve the misfires first.

As xalty mentioned, the misfire detection on the X300 is poor, and we've seen many cases of misfires reported in certain cylinders only to later discover entirely different cylinders were misfiring.

One thing worth doing is to carefully examine the wiring to your ignition coils. The insulation becomes brittle with heat and age and cracks and falls off, leading to shorts. The worst spot is the bend in the harness at the rear of the cylinder head. Inspection usually requires carefully cutting away the wrap around the harness.

Cheers,

Don

 

Any other options, the wires seem fine but im still gonna get new coils, maybe some spark plug seals idk im at awe with this one

 

Replace the spark plugs and clean the oil from the spark plug tubes while you're at it. The oil means your spark plug tube seals are leaking, which means you need to replace the camshaft cover gasket and tube seals (an easy job as long as your magnesium cam cover has not eroded inside).

The only spark plug to use is the OE Champion RC12YC / 711. They are deceptively inexpensive, but AJ16 engines seem to run better on them than any other plugs, including very expensive platinums and iridiums.

Have you checked for an obstructed air filter, or for a crack in an air intake pipe or loose or disconnected vacuum or crankcase breather hose?

Cheers,

Don

 

Will do that, im sure theres a guide to it somewhere on here. But would the seals being bad cause this many misfires ? And also i replaced them with some other ones not the champions but that’s definitely changing soon. Also no obstructions, when i cleaned the MAF sensor and throttle body i didn't notice any cracks but then again i wasn't looking. I was very careful putting it all back together as well.Dont know how to check vacuum and i have made sure all hoses are good

 

The reason the oil in the spark plug tubes can cause misfires is that the threaded shell of the spark plug is the electrical connection to the engine, which is the ground path for spark. When oil, which is an insulator, seeps down the threads of the plugs, it interrupts the ground path. This causes weak or no spark.

 

So i unplugged the MAF sensor while the engine was running and got nothing. It didnt change anything really i also noticed some cuts on the wiring for the sensor. But would that be causing a misfire in all cylinders?

 

The MAF sensor tells the Engine Control Module the volume of air entering the engine so it can adjust the air-fuel ratio accordingly. If the signal from the MAFS is incorrect or missing, the ECM cannot supply the correct amount of fuel, which can easily lead to misfires at some or all rpm. Misfires can trigger O2S codes due to excessive amounts of fuel in the exhaust. So you may have found your core issue. Say thanks to xalty, who suggested it first!

Cheers,

Don

 

if you had the elm scanner you can read live data from your phone. maf flow rate, throttle position, 02 sensor data,and fuel trims especially. without it you’re blind and throwing parts at the problem.